Executing transactions based on blockchain

ABSTRACT

At a node device associated with a blockchain as a received target transaction, a target transaction published by a user is received, where the received target transaction includes transaction content, and where at least a part of the transaction content includes a content summary associated with target content that is stored in a third-party storage system connected to the blockchain. By the node device and to the third-party storage system, the target content corresponding to the content summary is queried. By the node device, whether the target content is verified is determined. In response to determining that the target content is verified, by the node device, the received target transaction is executed based on the transaction content. By the node device, the received target transaction is stored in a distributed database associated with the blockchain.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. application Ser. No. 16/287,590filed Feb. 27, 2019, which claims priority to Chinese Patent ApplicationNo. 201810162067.3, filed on Feb. 27, 2018. The contents of the priorU.S. and Chinese applications are hereby incorporated by reference intheir entirety.

TECHNICAL FIELD

One or more implementations of the present disclosure relate to thefield of blockchain technologies, and in particular, to a method, anapparatus, and an electronic device for executing transactions based ona blockchain.

BACKGROUND

Blockchain technology, also known as a distributed ledger technology, isan emerging technology in which several computing devices participate in“accounting” to jointly maintain a complete distributed database. Theblockchain technology has the characteristics of decentralization,openness, and transparency, each computing device can participate indatabase recording, and data can be quickly synchronized betweencomputing devices. Therefore, the blockchain technology is used to buildthe decentralized system, and various execution programs are recorded inthe distributed database of the blockchain and are automaticallyexecuted, which has been widely used in many fields. For example, in thefield of financial technology, using the blockchain technology to builda P2P payment platform and publishing executive programs such as smartcontracts on the blockchain can implement point-to-point secure paymentbetween different users without financial institutions such as banks.

SUMMARY

The present specification discloses a method for executing transactionsbased on a blockchain, including: receiving, by a node device of ablockchain, a target transaction, where at least a part of transactioncontent in the target transaction includes a content summary of targetcontent stored in a third-party storage system connected to theblockchain; querying, to the third-party storage system, target contentcorresponding to the content summary, and verifying the target content;and if the verification of the target content succeeds, executing thetarget transaction based on the transaction content in the targettransaction, and storing the target transaction in a distributeddatabase of the blockchain after the target transaction is executed.

Optionally, the third-party storage system stores a mapping relationshipbetween the target content and the content summary of the targetcontent; and the querying, to the third-party storage system, targetcontent corresponding to the content summary includes: using the contentsummary as a query index and initiating a query to the third-partystorage system to query the target content corresponding to the contentsummary.

Optionally, the verifying the target content includes: calculating acontent summary of the target content based on a preset summaryalgorithm; determining whether the content summary obtained throughcalculation is consistent with the content summary of the target contentin the target transaction; and if the content summary obtained throughcalculation is consistent with the content summary of the target contentin the target transaction, determining that the verification of thetarget content succeeds.

Optionally, the third-party storage system includes a centralizedcontent-addressable-storage (CAS) system, or a distributed CAS system.

Optionally, the blockchain includes any member blockchain in aconsortium blockchain composed of a plurality of member blockchains.

Optionally, the third-party storage system is another member blockchainin the consortium blockchain that has a cross-chain data referencerelationship with the described blockchain.

Optionally, the consortium blockchain is a directed acyclic graph (DAG)structure constructed based on a cross-chain data reference relationshipbetween member blockchains.

The present specification further discloses an apparatus for executingtransactions based on a blockchain, including: a receiving module,configured to receive a target transaction, where at least a part oftransaction content in the target transaction includes a content summaryof target content stored in a third-party storage system connected tothe blockchain; a query module, configured to query, to the third-partystorage system, target content corresponding to the content summary, andverify the target content; and an execution module, configured to: ifthe verification of the target content succeeds, execute the targettransaction based on the transaction content in the target transaction,and store the target transaction in a distributed database of theblockchain after the target transaction is executed.

Optionally, the third-party storage system stores a mapping relationshipbetween the target content and the content summary of the targetcontent; and the query module is configured to: use the content summaryas a query index and initiate a query to the third-party storage systemto query the target content corresponding to the content summary.

Optionally, the execution module is further configured to: calculate acontent summary of the target content based on a preset summaryalgorithm; determine whether the content summary obtained throughcalculation is consistent with the content summary of the target contentin the target transaction; and if the content summary obtained throughcalculation is consistent with the content summary of the target contentin the target transaction, determine that the verification of the targetcontent succeeds.

Optionally, the third-party storage system includes a centralizedcontent-addressable-storage (CAS) system, or a distributed CAS system.

Optionally, the blockchain includes any member blockchain in aconsortium blockchain composed of a plurality of member blockchains.

Optionally, the third-party storage system is another member blockchainin the consortium blockchain that has a cross-chain data referencerelationship with the described blockchain.

Optionally, the consortium blockchain is a directed acyclic graph (DAG)structure constructed based on a cross-chain data reference relationshipbetween member blockchains.

The present specification further discloses an electronic apparatus,including: a processor; and a memory, configured to store amachine-executable instruction, where by reading and executing themachine-executable instruction that is stored in the memory andcorresponding to a transaction execution control logic based on ablockchain, the processor is configured to: receive a targettransaction, where at least a part of transaction content in the targettransaction includes a content summary of target content stored in athird-party storage system connected to the blockchain; query, to thethird-party storage system, target content corresponding to the contentsummary, and verify the target content; and if the verification of thetarget content succeeds, execute the target transaction based on thetransaction content in the target transaction, and store the targettransaction in a distributed database of the blockchain after the targettransaction is executed.

According to the previously described implementations, the contentsummary of the target content stored in the third-party storage systemconnected to the blockchain is carried in the transaction content of thetransaction published to the blockchain. As such, the node devicereceiving the transaction in the blockchain can query the third-partystorage system for the corresponding target content based on the contentsummary, verify the target content, execute the transaction after theverification of the target content succeeds, and store the transactionin the distributed database of the blockchain after the transaction isexecuted. As such, a user can refer to the target content stored in thethird-party storage system connected to the blockchain as thetransaction content in the transaction published to the blockchain so asto alleviate redundant storage of data in the blockchain caused bysynchronizing the original content of the target content stored in theabove-mentioned third-party storage system to each node device in theblockchain.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flowchart illustrating a method for executing transactionsbased on a blockchain, according to an example implementation;

FIG. 2 is a schematic structural diagram illustrating a consortiumblockchain, according to an example implementation;

FIG. 3 is a schematic structural diagram illustrating an electronicdevice, according to an example implementation;

FIG. 4 is a block diagram illustrating an apparatus for executingtransactions based on a blockchain, according to an exampleimplementation; and

FIG. 5 is a flowchart illustrating an example of a computer-implementedmethod for executing a transaction based on a blockchain, according toan implementation of the present disclosure.

DESCRIPTION OF IMPLEMENTATIONS

In the traditional blockchain transaction process, transaction contentin a transaction (transfer) usually comes from data content stored in adistributed database (namely a blockchain ledger) of the blockchain, anddata content stored in an external storage cannot be referred to.Therefore, for each node device in the blockchain network, when atransaction published by a member accessing the blockchain is executed,data content involved in the transaction content is all from the chain,and thus a “data use closed loop” is formed.

The present specification intends to disclose a technical solution forbreaking the “data use closed loop” of the blockchain by referencingimmutable data content stored in a third-party storage platform astransaction content in a blockchain transaction (transfer).

In implementation, the blockchain can be connected to a third-partystorage system in advance. The third-party storage system can pre-storesome immutable data content that can be referred to by the transactionpublished on the blockchain. When a member accessing the blockchainpublishes a transaction to the blockchain, a content summary of the datacontent stored in the third-party storage system can be added to thetransaction to refer to the data content stored in the third-partystorage system as the transaction content.

When the node device on the blockchain receives a transaction publishedby the member, the node device can initiate a query to the third-partystorage system based on the content summary to query the data contentcorresponding to the content summary and verify the data content that isqueried. If verification of the content succeeds, the transaction can beexecuted based on the complete transaction content in the transaction,and the transaction is stored in the distributed database of theblockchain after the transaction is completed.

In the described implementation, the content summary of the targetcontent stored in the third-party storage system connected to theblockchain is carried in the transaction content of the transactionpublished to the blockchain. As such, the node device receiving thetransaction in the blockchain can query the third-party storage systemfor the corresponding target content based on the content summary,verify the target content, execute the transaction after theverification of the target content succeeds, and store the transactionin the distributed database of the blockchain after the transaction isexecuted. As such, the user can refer to the target content stored inthe third-party storage system connected to the blockchain as thetransaction content in the transaction published to the blockchain so asto alleviate redundant storage of data in the blockchain caused bysynchronizing the original content of the target content stored in thethird-party storage system to each node device in the blockchain.

The present specification is described below by using specificimplementations with reference to specific application scenarios.

FIG. 1 shows a method for executing transactions based on a blockchainprovided in an implementation of the present specification. The methodis applied to a node device in the blockchain, and the node deviceperforms the following steps.

Step 102. A node device of a blockchain receives a target transaction;where at least a part of transaction content in the target transactionincludes a content summary of target content stored in a third-partystorage system connected to the blockchain.

Step 104. Query, to the third-party storage system, target contentcorresponding to the content summary, and verify the target content.

Step 106. If the verification of the target content succeeds, executethe target transaction based on the transaction content in the targettransaction, and store the target transaction in a distributed databaseof the blockchain after the target transaction is executed. Theblockchain described in the present specification can include anyblockchain network where immutable data content stored in thethird-party storage system connected to the blockchain can be referencedas the transaction content in the supported blockchain transaction.

For example, in a scenario, the previously described blockchain can beany member blockchain in a consortium blockchain composed of a pluralityof member blockchains. In a blockchain transaction supported in eachmember blockchain in the consortium blockchain, data content stored inother member blockchains can be referenced as transaction content acrossthe chain.

The previously described third-party storage system includes acontent-addressable-storage (CAS) platform that provides reliable datastorage services for the blockchain. The so-called content addressablemeans that data is no longer addressed by using a storage offset of thedata in a storage system but addressed by using content of the data.

In the CAS platform, a content summary of the stored data content (suchas a content hash value obtained through hash calculation for the datacontent) can be used as a query index of the original data content, anda mapping relationship between the query index and the original datacontent is stored. As such, the data querying party can query thecorresponding original data content from the CAS platform by using thecontent summary as the query index.

In actual applications, the previously described third-party storagesystem can include a traditional centralized content-addressable-storage(CAS) system; or can include a decentralized distributed CAS system.

For example, in a scenario, the previously described blockchain can beany member blockchain in a consortium blockchain composed of a pluralityof member blockchains. The previously described third-party storagesystem can be specifically, for example, a distributed system based onan Object Storage Service (OSS) architecture that is deployed in theconsortium blockchain and can be connected to each member blockchain inthe consortium blockchain.

Alternatively, in another example, another member blockchain, in thepreviously described consortium blockchain other than the describedblockchain, that has a cross-chain data reference relationship with thedescribed blockchain can be used as the third-party storage systemconnected to the described blockchain to implement cross-chain datareference between the member blockchains.

The following describes in detail the technical solutions of the presentspecification by using an example that the previously-describedblockchain is a member blockchain in the consortium blockchainconsisting of a plurality of member blockchains with reference to“third-party storage system deployment”, “transaction contentreference”, “transaction content addressing”, and “transactionexecution”.

(1) Third-Party Storage System Deployment

In the present specification, an operator can pre-establish a consortiumblockchain consisting of a plurality of member blockchains. Each memberblockchain in the consortium blockchain is a consortium member in theconsortium blockchain. The previously described blockchain can be anymember blockchain in the consortium blockchain.

The operator of the consortium blockchain can also deploy a third-partystorage system in the consortium blockchain to connect to the memberblockchains in the consortium blockchain and provide reliable datastorage services for the member blockchains.

For example, the described third-party storage system can provide acontinuous and reliable API access interface for each member blockchainso that the member blockchains in the consortium blockchain can connectto the third-party storage system by accessing the API access interface.

When a third-party storage system is deployed in the consortiumblockchain, a global third-party storage system can be deployed for theconsortium blockchain, or one independent third-party storage system canbe deployed for each member blockchain in the consortium blockchain.Implementations are not limited in this specification.

In the present specification, the described third-party storage systemcan be a CAS system that supports content addressability. In actualapplications, the described third-party storage system can be atraditional centralized CAS system, or can be a distributed CAS system.

The described distributed CAS system can include a traditionalcentralized distributed system and a decentralized distributed system.

In an implementation, the third-party storage system can bespecifically, for example, a centralized distributed system based on anOSS architecture that is deployed in the consortium blockchain and canbe connected to each member blockchain in the consortium blockchain.

In another implementation, the described third-party storage system canalso be a decentralized distributed system. In implementation, anothermember blockchain, in the previously described consortium blockchainother than the described blockchain, that has a cross-chain datareference relationship with the described blockchain can be used as thethird-party storage system connected to the described blockchain. Inother words, any member blockchain in the consortium blockchain can beused as a third-party storage system connected to another memberblockchain to implement cross-chain data reference.

For example, in a scenario, an operator can establish a consortiumblockchain based on actual service needs and assign different serviceroles to member blockchains in the consortium blockchain. In otherwords, the consortium blockchain corresponds to a complete serviceprocess, and each member blockchain can correspond to one sub-process inthe complete service process.

In an example of a consortium blockchain established by the operatorbased on the service need of “online leasing transaction”, memberblockchains constituting the consortium blockchain can include a“transaction chain”, an “authentication chain”, and a “data chain”. The“transaction chain”, the “authentication chain”, and the “data chain”can each correspond to a sub-process in the “online leasing transaction”service process. For example, the “data chain” is used to maintainreal-name data of the leasing user; the “authentication chain” is usedto complete leasing real-name authentication for the user; and the“transaction chain” is used to complete the online leasing transaction.

Then the operator can construct the consortium blockchain to a topologymap with a directed acyclic graph (DAG) structure at the service levelbased on a one-way cross-chain data reference relationship betweenmember blockchains.

It is worthwhile to note that the one-way cross-chain data referencerelationship between the member blockchains usually depends on actualservice needs, and is not particularly limited in the presentspecification.

For example, FIG. 2 is a schematic diagram illustrating a consortiumblockchain with the DAG structure in an example.

As shown in FIG. 2, still in the example of a consortium blockchainestablished by the operator based on the service need of “online leasingtransaction”, member blockchains constituting the consortium blockchaincan include a “transaction chain”, an “authentication chain”, and a“data chain”. The “data chain” is used to maintain real-name data of theleasing user, and the user can store the personal real-name data in adistributed database of the “data chain” by publishing a transaction onthe “data chain”. The “authentication chain” is used to refer to thereal-name data of the user published on the “data chain” to completeleasing real-name authentication for the user. The user can complete thepersonal real-name authentication by publishing a transaction on the“authentication chain” and publish the real-name authentication resultin a distributed database of the “authentication chain”. The“transaction chain” is used to refer to the real-name authenticationresult for the user that is published on the “authentication chain”. Theuser can complete the online leasing transaction by publishing atransaction on the “transaction chain” and publish the transactionresult in a distributed database of the “authentication chain”.

Another member blockchain having a cross-chain data referencerelationship with any target member blockchain in the previouslydescribed consortium blockchain is used as a distributed storageplatform connected to the target member blockchain. Therefore,cross-chain data reference between the member blockchains can beimplemented at the service level. In addition, the member blockchainused as the third-party storage system no longer needs to synchronizethe original content of the previously described referenced targetcontent to each node device in the previously described target memberblockchain, and the target member blockchain does not need to store theoriginal content of the previously described target content. As such,the target member blockchain does not need to perform additional dataassociation for the original content of the target content stored in thetarget member blockchain and the referenced target content synchronizedby the member blockchain used as the third-party storage system.Therefore, data association of the referenced target content on twodifferent blockchains can be achieved by using only the content summaryof the referenced target content, and it can be ensured that the targetcontent referenced by the previously described target member blockchainand the referenced target content stored on the member blockchain usedas the third-party storage system are consistent in business semantics.

(2) Transaction Content Reference

In the present specification, a user who needs to access the consortiumblockchain can register with the consortium blockchain in advance toobtain a pair of public and private keys returned by the consortiumblockchain. After the registration is completed, the consortiumblockchain can create a corresponding account object for the user.

The registered user can access each member blockchain through the APIinterface provided by each member blockchain in the consortiumblockchain, and complete corresponding service operations in each memberblockchain by publishing a transaction that is signed based on the heldprivate key to each member blockchain. For example, taking the“transaction chain” in the consortium blockchain shown in FIG. 2 as anexample, the user can complete the online leasing transaction bypublishing a transaction in the “transaction chain”.

In implementation, the operator of the consortium blockchain can developclient software (such as APP) for members accessing the consortiumblockchain, and the members can assemble transaction data through theclient software based on the standard transaction format supported bythe consortium blockchain, and invoke the API interface provided by eachmember blockchain to publish the assembled transaction data to thetarget member blockchain specified by the member in the consortiumblockchain for execution.

The transaction data assembled by the member through the client softwarecan carry the transaction content specified by the member, and at leasta part of the transaction content can be replaced by a content summary.

In an implementation, the member can fill in the transaction contentthrough the client software when assembling the transaction data thatneeds to be executed on the target member blockchain through the clientsoftware. The client software can parse the transaction content filledby the member to determine whether the transaction content filled by themember exists in the third-party storage system that is connected to thetarget member blockchain.

If the transaction content filled by the member exists in thetransaction content stored in the third-party storage system, thethird-party storage system can be queried for the content summary (thatis, the query index) corresponding to the transaction content.Alternatively, a content summary for the part of the transaction contentis recalculated based on the same content summary algorithm supported bythe third-party storage system, and then the content summary is filledin a marked transaction format.

For example, in implementation, a content summary field for carryingtransaction content can be extended in a standard transaction formatsupported by the consortium blockchain. When the client softwareassembles the transaction data based on the standard transaction format,content summaries of all transaction content already stored in thepreviously described third-party storage system can be filled in thecontent summary field.

(3) Transaction Content Addressing

The node device that is connected to the registered member user in thepreviously described target member blockchain in the presentspecification can first perform identity authentication on the userbased on a public key corresponding to the private key held by themember after receiving the transaction published by the user based onthe private key.

For example, in actual applications, a user can sign an initiatedtransaction based on a private key held, and a node device in theblockchain can attempt to authenticate the signature based on a publickey corresponding to the private key held by the user. If the signaturehas been authenticated, identity authentication of the user succeeds.

After the identity authentication of the user succeeds, the node devicecan parse transaction content carried in the received transaction todetermine whether a content summary exists in the transaction contentcarried in the transaction.

For example, the node device can determine whether a content summaryexists in the transaction content carried in the transaction, throughparsing whether a content summary field for carrying the transactioncontent extended in the standard transaction format is a null value.

If the content summary exists in the transaction content carried in thetransaction, it indicates that a part of the transaction content in thetransaction is the reference of the data content already stored in thedescribed third-party storage system. In this case, in order to obtainthe complete transaction content carried in the transaction, the nodedevice can query the third-party storage system that is connected to thetarget member blockchain for the target content corresponding to thecontent summary.

In implementation, the node device can set up a query request, use thecontent summary as a query index, add the content summary to the queryrequest, and then submit the query request to the third-party storagesystem. After receiving the query request, the third-party storagesystem can read the query index from the query request, then traversethe mapping relationship between the locally stored data content and thecontent summary based on the query index to search for the targetcontent corresponding to the query index, and return the target contentto the node device.

It is worthwhile to note that, in actual applications, in addition tothe content summary used as the query index, the described query requestcan further carry some auxiliary query parameters to facilitate quickquery of the target content corresponding to the content summary.

For example, the third-party storage system connected to the targetmember blockchain is another member blockchain in the consortiumblockchain that has a cross-chain data reference relationship with thetarget member blockchain. In this case, because the referenced datacontent and the corresponding content summary stored in the other memberblockchain serving as the third-party storage system are usually storedin a distributed database of the blockchain in the form of a block, thedescribed query request can further carry the number of the member blockchain in which the content summary is located, the block number, etc. asauxiliary query parameters to facilitate the query.

(4) Transaction Execution

In the present specification, after the node device identifies thetarget content corresponding to the content summary carried in thereceived transaction from the third-party storage system that isconnected to the target member blockchain, the node device can executethe transaction in the target member blockchain based on the completetransaction content carried in the transaction.

First, the node device can verify the identified target content toensure that the identified target content is consistent with the datacontent corresponding to the content summary.

In implementation, the node device can recalculate a content summary ofthe target content that is identified, and then match the contentsummary obtained through recalculation with the content summary carriedin the received transaction to determine whether the content summaryobtained through recalculation is consistent with the content summarycarried in the received transaction.

If the content summary obtained through recalculation is consistent withthe content summary carried in the received transaction, theverification of the identified target content succeeds, the transactionreceived by the node device is a valid transaction, and the node devicecan obtain the complete transaction content carried in the transaction.

If the content summary obtained through recalculation is inconsistentwith the content summary carried in the received transaction, theverification of the identified target content fails. In this case, theoriginal referenced target content stored in the described third-partystorage system is probably modified and updated due to the unreliabilityof the system, the transaction is an invalid transaction, and the nodedevice can directly terminate the transaction.

It is worthwhile to note that, when the node device recalculates thecontent summary of the identified target content, a data structure ofthe target content, a method of encoding the target content, and asummary algorithm used are all required to be consistent with those inthe third-party storage system so as to ensure that the node device andthe third-party storage system can obtain the same calculation resultwhen performing content summary calculation for the same target content.

Further, the node device can further perform consensus processing on avalid transaction (that is, a transaction whose content has beenauthenticated) received during a period of time based on the consensusalgorithm supported by the target member blockchain, and execute thetransaction in the target member blockchain based on the completetransaction content carried in the transaction after the consensusprocessing is completed.

The consensus algorithm supported by each member blockchain in theconsortium blockchain is not particularly limited in the presentspecification, and the consensus algorithms supported by the memberblockchains can be the same or different.

It is worthwhile to note that, in the present specification, when thenode device executes the transaction in the target member blockchainbased on the complete transaction content in the obtained transaction,generally the following two situations can be included.

In one situation, the transaction that the member user publishes in thepreviously described target member blockchain can specifically be atransaction executed automatically by invoking a smart contractpublished in the target member blockchain. For example, the describedtransaction can specifically be an online value transfer (such as across-border transfer) completed in the blockchain by invoking a smartcontract.

In this case, an execution program that can be invoked and associatedwith the transaction can be pre-declared in the smart contract. Forexample, the execution program can specifically be executable code,function, etc. related to the transaction condition declared in thesmart contract; and the transaction content carried in the transactionis used as an input parameter for invoking the smart contract. Afterobtaining the transaction content carried in the transaction, the nodedevice can initiate an invocation to the smart contract and submit theinput parameters to the execution program declared in the smart contractfor execution to complete the transaction.

In the other situation, the transaction that the member user publishesin the previously described target member blockchain can specifically bea standard transaction supported by the target member blockchain. Thestandard transaction can be completed without invoking the smartcontract. For example, the described transaction can specifically be atransaction supported by the previously described target memberblockchain such as “certificate transaction”. For example, as shown inthe “data chain” in FIG. 2, the user can publish a “certificatetransaction” to the “data chain” and store real name information of theuser in a distributed database of the “data chain”, and once thetransaction is published, the real name information of the user cannotbe tampered with.

In this case, the node device can first check validity of thetransaction when executing the transaction. If the validity checkconfirms that the transaction is valid, the node device can furtherbroadcast the transaction in the target member blockchain andsynchronize the transaction to other node devices in the target memberblockchain, and other node devices check the validity of thetransaction. If most of the node devices in the target member blockchain(such as 51%) have validated the transaction and confirmed that thetransaction is valid, the transaction is completed.

In the present specification, after the node device executes thereceived transaction, the node device can further store the transactionin the distributed database of the target member blockchain.

Information recorded in the distributed database of the blockchainusually includes a transaction log and a transaction state.

The transaction log is used for storing a log of the transactions,includes a series of blocks in the order of occurrence, and is atransaction record in the distributed database.

The transaction state is used to store state changes caused bytransactions recorded in the distributed database. For example, ablockchain usually includes many small objects (such as account objects,contract objects, asset objects, etc.), each time a transaction issubmitted in a distributed database of the blockchain, after thetransaction is completed, states related to the transaction will beupdated synchronously. For example, taking the online transfertransaction submitted in the blockchain as an example, after theexecution of the transaction, the balance of the account object relatedto the transfer will be updated synchronously.

In this case, after the node device executes the received transaction,the node device can further store the transaction in the distributeddatabase of the target member blockchain.

In one aspect, the transaction can be written into the transaction logstored in the distributed database of the target member blockchain inthe generated block.

In the other aspect, state changes of related objects caused by thetransaction can be updated in the transaction state. For example, stilltaking the online transfer transaction submitted in the blockchain as anexample, after the execution of the transaction, the balance of theaccount object related to the transfer can be updated in the transactionstate.

In the previous implementation, the original content of the referenceddata can be stored in the third-party storage system, and only thecontent summary of the referenced data content is stored in theblockchain. When the blockchain performs a transaction or performstransaction tracing, the blockchain reads the original content of thereferenced data from the third-party storage system based on the contentsummary.

As such, it can alleviate redundant storage of data in the blockchainthat is caused by synchronizing the original content of the targetcontent stored in the previously described third-party storage system toeach node device on the blockchain.

For example, the third-party storage system connected to the targetblockchain is another blockchain that has a cross-chain data referencerelationship with the described blockchain is used as an example. Assumethat the other blockchain includes 5 node devices, and the targetblockchain includes 50 node devices. If the method of synchronizingreferenced data content stored in the other blockchain to the targetblockchain is still used, the referenced data content needs to besynchronized to 50 nodes in the target blockchain, causing a largeamount of redundancy of the referenced data content in the targetblockchain. However, if the target blockchain only stores the contentsummary of the referenced data content, the other blockchain no longerneeds to separately synchronize the referenced data content to the 50node devices, thereby significantly reducing the data storage redundancyof the described target blockchain.

In addition, the storage performance of the blockchain can besignificantly improved.

For example, in actual applications, if the previously describedreferenced data content is a large media file such as a picture or avideo, the storage performance of the blockchain network is reduced ifthese media files are directly stored in the described target memberblockchain. Therefore, the data storage performance of the describedtarget member blockchain can also be improved to some extent by usingthe method.

Corresponding to the previously described method implementation, thepresent specification further provides an implementation of an apparatusfor executing transactions based on a blockchain. The implementation ofthe apparatus for executing transactions based on a blockchain in thepresent specification can be applied to an electronic device. The deviceimplementation can be implemented by software, or can be implemented byhardware or a combination of hardware and software. Softwareimplementation is used as an example. As a logical device, the device isformed by reading a corresponding computer program instruction in anon-volatile memory to a memory by a processor of an electronic devicewhere the device is located. In terms of hardware, referring to FIG. 3,FIG. 3 is a hardware structural diagram illustrating an electronicdevice where the apparatus for executing transactions based on ablockchain is located in the present specification. In addition to aprocessor, a memory, a network interface, and a non-volatile memoryshown in FIG. 3, the electronic device where the apparatus is located inthe implementations can usually include other hardware based on anactual function of the electronic device. Details are omitted here forsimplicity.

FIG. 4 is a block diagram illustrating an apparatus for executingtransactions based on a blockchain, according to an exampleimplementation of the present specification.

Referring to FIG. 4, the apparatus 30 for executing transactions basedon a blockchain can be applied to the electronic device shown in FIG. 2,and includes a receiving module 401, a query module 402, and anexecution module 403.

The receiving module 401 is configured to receive a target transaction,where at least a part of transaction content in the target transactionincludes a content summary of target content stored in a third-partystorage system connected to the blockchain.

The query module 402 is configured to query, to the third-party storagesystem, target content corresponding to the content summary, and verifythe target content.

The execution module 403 is configured to: if the verification of thetarget content succeeds, execute the target transaction based on thetransaction content in the target transaction, and store the targettransaction in a distributed database of the blockchain after the targettransaction is executed.

In the present implementation, the third-party storage system stores amapping relationship between the target content and the content summaryof the target content; and the query module 402 is configured to: usethe content summary as a query index and initiate a query to thethird-party storage system to query the target content corresponding tothe content summary.

In the present implementation, the execution module 403 is furtherconfigured to: calculate a content summary of the target content basedon a preset summary algorithm; determine whether the content summaryobtained through calculation is consistent with the content summary ofthe target content in the target transaction; and if the content summaryobtained through calculation is consistent with the content summary ofthe target content in the target transaction, determine that theverification of the target content succeeds.

In the present implementation, the third-party storage system includes acentralized content-addressable-storage (CAS) system, or a distributedCAS system.

In the present implementation, the blockchain includes any memberblockchain in a consortium blockchain composed of a plurality of memberblockchains.

In the present implementation, the third-party storage system is anothermember blockchain in the consortium blockchain that has a cross-chaindata reference relationship with the described blockchain.

In the present implementation, the consortium blockchain is a directedacyclic graph (DAG) structure constructed based on a cross-chain datareference relationship between member blockchains.

For an implementation process of functions and roles of each module inthe apparatus, references can be made to an implementation process of acorresponding step in the previous method. Details are omitted here forsimplicity.

Because an apparatus implementation basically corresponds to a methodimplementation, for related parts, references can be made to relateddescriptions in the method implementation. The previously describedapparatus implementation is merely an example. The modules described asseparate parts can or cannot be physically separate, and parts displayedas modules can or cannot be physical modules, can be located in oneposition, or can be distributed on a plurality of network modules. Someor all of the modules can be selected based on actual needs to achievethe objectives of the solutions of the present specification. A personof ordinary skill in the art can understand and implement theimplementations of the present application without creative efforts.

The system, apparatus, or module illustrated in the previousimplementations can be implemented by using a computer chip or anentity, or can be implemented by using a product having a certainfunction. A typical implementation device is a computer, and thecomputer can be a personal computer, a laptop computer, a cellularphone, a camera phone, a smart phone, a personal digital assistant, amedia player, a navigation device, an email receiving and sendingdevice, a game console, a tablet computer, a wearable device, or anycombination of these devices.

Corresponding to the previously described method implementation, thepresent specification further provides an implementation of anelectronic device. The electronic device includes a processor and amemory configured to store a machine-executable instruction, where theprocessor and the memory are usually connected to each other through aninternal bus. In another possible implementation, the device can alsoinclude an external interface to enable communication with other devicesor components.

In the present implementation, by reading and executing themachine-executable instruction that is stored in the memory andcorresponding to a transaction execution control logic based on ablockchain, the processor is configured to: receive a targettransaction, where at least a part of transaction content in the targettransaction includes a content summary of target content stored in athird-party storage system connected to the blockchain; query, to thethird-party storage system, target content corresponding to the contentsummary, and verify the target content; and if the verification of thetarget content succeeds, execute the target transaction based on thetransaction content in the target transaction, and store the targettransaction in a distributed database of the blockchain after the targettransaction is executed.

In the present implementation, the third-party storage system stores amapping relationship between the target content and the content summaryof the target content; and by reading and executing themachine-executable instruction that is stored in the memory andcorresponding to the transaction execution control logic based on ablockchain, the processor is configured to: use the content summary as aquery index and initiate a query to the third-party storage system toquery the target content corresponding to the content summary.

In the present implementation, by reading and executing themachine-executable instruction that is stored in the memory andcorresponding to the transaction execution control logic based on ablockchain, the processor is configured to: calculate a content summaryof the target content based on a preset summary algorithm; determinewhether the content summary obtained through calculation is consistentwith the content summary of the target content in the targettransaction; and if the content summary obtained through calculation isconsistent with the content summary of the target content in the targettransaction, determine that the verification of the target contentsucceeds.

A person of ordinary skilled in the art can easily figure out anotherimplementation of the present specification after thinking over thespecification and practicing the present disclosure here. The presentspecification is intended to cover any variations, uses, or adaptationsof the present specification, and these variations, uses, or adaptationsfollow the general principles of the present specification and includecommon knowledge or conventional techniques that are not disclosed inthe technical field of the present specification. The specification andthe implementations are merely considered as examples, and the actualscope and the spirit of the present specification are pointed out by thefollowing claims.

It should be understood that the present specification is not limited tothe precise structures that have been described above and shown in thedrawings, and various modifications and changes can be made withoutdeparting from the scope of the present disclosure. The scope of thepresent specification is limited by the appended claims only.

The previous descriptions are merely preferred implementations of thepresent specification, but are not intended to limit the presentspecification. Any modification, equivalent replacement, or improvementmade without departing from the spirit and principle of the presentspecification shall fall within the protection scope of the presentspecification.

FIG. 5 is a flowchart illustrating an example of a computer-implementedmethod 500 for executing a transaction based on blockchain, according toan implementation of the present disclosure. For clarity ofpresentation, the description that follows generally describes method500 in the context of the other figures in this description. However, itwill be understood that method 500 can be performed, for example, by anysystem, environment, software, and hardware, or a combination ofsystems, environments, software, and hardware, as appropriate. In someimplementations, various steps of method 500 can be run in parallel, incombination, in loops, or in any order.

At 502, at a node device associated with a blockchain as a receivedtarget transaction, a target transaction published by a user isreceived, where the received target transaction includes transactioncontent, and where at least a part of the transaction content includes acontent summary associated with target content that is stored in athird-party storage system connected to the blockchain.

In some implementations, the blockchain is a member blockchainassociated with a consortium blockchain network, wherein the consortiumblockchain network comprises a number of member blockchains, and whereeach member blockchain in the consortium blockchain network is athird-party storage system connected to another member blockchain toimplement a cross-chain data reference.

In some implementations, the third-party storage system includes acontent-addressable-storage (CAS) platform that provides a data storageservice for the number of the member blockchains, where the CAS platformuses the content summary of the stored target content as a query indexof the target content, and where the CAS platform stores a mappingrelationship between the query index and the target content. From 502,method 500 proceeds to 504.

At 504, by the node device and to the third-party storage system, thetarget content corresponding to the content summary is queried. From504, method 500 proceeds to 506.

At 506, by the node device, whether the target content is verified isdetermined. In some implementations, determining whether the targetcontent is verified includes identifying, by the node device asidentified target content, the target content corresponding to thecontent summary carried in the received target transaction;recalculating, by the node device as recalculated content summary, thecontent summary of the identified target content; determining, by thenode device, whether the recalculated content summary matches thecontent summary carried in the received target transaction; if it isdetermined that the recalculated content summary matches the contentsummary carried in the received target transaction: determining that thetarget content is verified and that the received target transaction is avalid transaction; and obtaining complete transaction content carried inthe received target transaction; or if it is determined that therecalculated content summary does not match the content summary carriedin the received target transaction: determining that the target contentis not verified and that the received target transaction is invalid; andterminating the received target transaction. From 506, method 500proceeds to 508.

At 508, in response to determining that the target content is verified,by the node device, the received target transaction is executed based onthe transaction content.

In some implementations, executing the received target transaction basedon the transaction content comprises automatically executing thereceived target transaction based on the complete transaction content byinvoking a smart contract published in the blockchain.

In some implementations, the received target transaction published bythe user is a standard transaction supported by the blockchain, andwhere executing the received target transaction includes determining, bythe node device, whether the received target transaction is valid; inresponse to determining that the received target transaction is valid,broadcasting, by the node device, the received target transaction in theblockchain; synchronizing, by the node device, the received targettransaction to other node devices in the blockchain to allow the othernode devices to check a validity of the received target transaction; ifa predetermined number of the other node devices determine that thereceived target transaction is valid, confirming, by the node device,that the received target transaction is valid and completing thereceived target transaction. From 508, method 500 proceeds to 510.

At 510, by the node device, the received target transaction is stored ina distributed database associated with the blockchain. In someimplementations, storing the received target transaction in thedistributed database comprises storing a transaction log and atransaction state of the received target transaction in the distributeddatabase. After 510, method 500 can stop.

Implementations of the present application can solve technical problemsin digital transaction execution processes. Traditionally, in ablockchain transaction process, transaction content in a transactionusually comes from data content stored in a distributed database of theblockchain, and data content stored in an external storage cannot bereferred to. Therefore, for each node device in the blockchain network,when a transaction published by a member accessing the blockchain isexecuted, data content involved in the transaction content is all fromthe blockchain, and thus a “data use closed loop” is formed. What isneeded is a technique to break a formed “data use closed loop” of theblockchain.

Implementation of the present application provide methods andapparatuses for improving blockchain based digital transaction executionby referencing immutable data content stored in a third-party storageplatform as transaction content in a blockchain transaction. Accordingto these implementations, the blockchain can be connected to athird-party storage system in advance. The third-party storage systemcan pre-store some immutable data content that can be referred to by thetransaction published on the blockchain. When a member accessing theblockchain publishes a transaction to the blockchain, a content summaryof the data content stored in the third-party storage system can beadded to the transaction to refer to the data content stored in thethird-party storage system as the transaction content. In addition, whenthe node device on the blockchain receives a transaction published bythe member, the node device can initiate a query to the third-partystorage system based on the content summary to query the data contentcorresponding to the content summary and verify the data content that isqueried. If verification of the content succeeds, the transaction can beexecuted based on the complete transaction content in the transaction,and the transaction is stored in the distributed database of theblockchain after the transaction is completed.

In some implementations, the described methods and apparatuses canalleviate redundant data storage in the blockchain that is caused bysynchronizing the original content of the target content stored in thepreviously described third-party storage system to each node device inthe blockchain. This is because original content of the referenced datacan be stored in the third-party storage system, and a content summaryof the referenced data content is stored in the blockchain. When theblockchain performs a transaction or performs transaction tracing, theblockchain reads the original content of the referenced data from thethird-party storage system based on the content summary.

Embodiments and the operations described in this specification can beimplemented in digital electronic circuitry, or in computer software,firmware, or hardware, including the structures disclosed in thisspecification or in combinations of one or more of them. The operationscan be implemented as operations performed by a data processingapparatus on data stored on one or more computer-readable storagedevices or received from other sources. A data processing apparatus,computer, or computing device may encompass apparatus, devices, andmachines for processing data, including by way of example a programmableprocessor, a computer, a system on a chip, or multiple ones, orcombinations, of the foregoing. The apparatus can include specialpurpose logic circuitry, for example, a central processing unit (CPU), afield programmable gate array (FPGA) or an application-specificintegrated circuit (ASIC). The apparatus can also include code thatcreates an execution environment for the computer program in question,for example, code that constitutes processor firmware, a protocol stack,a database management system, an operating system (for example anoperating system or a combination of operating systems), across-platform runtime environment, a virtual machine, or a combinationof one or more of them. The apparatus and execution environment canrealize various different computing model infrastructures, such as webservices, distributed computing and grid computing infrastructures.

A computer program (also known, for example, as a program, software,software application, software module, software unit, script, or code)can be written in any form of programming language, including compiledor interpreted languages, declarative or procedural languages, and itcan be deployed in any form, including as a stand-alone program or as amodule, component, subroutine, object, or other unit suitable for use ina computing environment. A program can be stored in a portion of a filethat holds other programs or data (for example, one or more scriptsstored in a markup language document), in a single file dedicated to theprogram in question, or in multiple coordinated files (for example,files that store one or more modules, sub-programs, or portions ofcode). A computer program can be executed on one computer or on multiplecomputers that are located at one site or distributed across multiplesites and interconnected by a communication network.

Processors for execution of a computer program include, by way ofexample, both general- and special-purpose microprocessors, and any oneor more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read-only memory ora random-access memory or both. The essential elements of a computer area processor for performing actions in accordance with instructions andone or more memory devices for storing instructions and data. Generally,a computer will also include, or be operatively coupled to receive datafrom or transfer data to, or both, one or more mass storage devices forstoring data. A computer can be embedded in another device, for example,a mobile device, a personal digital assistant (PDA), a game console, aGlobal Positioning System (GPS) receiver, or a portable storage device.Devices suitable for storing computer program instructions and datainclude non-volatile memory, media and memory devices, including, by wayof example, semiconductor memory devices, magnetic disks, andmagneto-optical disks. The processor and the memory can be supplementedby, or incorporated in, special-purpose logic circuitry.

Mobile devices can include handsets, user equipment (UE), mobiletelephones (for example, smartphones), tablets, wearable devices (forexample, smart watches and smart eyeglasses), implanted devices withinthe human body (for example, biosensors, cochlear implants), or othertypes of mobile devices. The mobile devices can communicate wirelessly(for example, using radio frequency (RF) signals) to variouscommunication networks (described below). The mobile devices can includesensors for determining characteristics of the mobile device's currentenvironment. The sensors can include cameras, microphones, proximitysensors, GPS sensors, motion sensors, accelerometers, ambient lightsensors, moisture sensors, gyroscopes, compasses, barometers,fingerprint sensors, facial recognition systems, RF sensors (forexample, Wi-Fi and cellular radios), thermal sensors, or other types ofsensors. For example, the cameras can include a forward- or rear-facingcamera with movable or fixed lenses, a flash, an image sensor, and animage processor. The camera can be a megapixel camera capable ofcapturing details for facial and/or iris recognition. The camera alongwith a data processor and authentication information stored in memory oraccessed remotely can form a facial recognition system. The facialrecognition system or one-or-more sensors, for example, microphones,motion sensors, accelerometers, GPS sensors, or RF sensors, can be usedfor user authentication.

To provide for interaction with a user, embodiments can be implementedon a computer having a display device and an input device, for example,a liquid crystal display (LCD) or organic light-emitting diode(OLED)/virtual-reality (VR)/augmented-reality (AR) display fordisplaying information to the user and a touchscreen, keyboard, and apointing device by which the user can provide input to the computer.Other kinds of devices can be used to provide for interaction with auser as well; for example, feedback provided to the user can be any formof sensory feedback, for example, visual feedback, auditory feedback, ortactile feedback; and input from the user can be received in any form,including acoustic, speech, or tactile input. In addition, a computercan interact with a user by sending documents to and receiving documentsfrom a device that is used by the user; for example, by sending webpages to a web browser on a user's client device in response to requestsreceived from the web browser.

Embodiments can be implemented using computing devices interconnected byany form or medium of wireline or wireless digital data communication(or combination thereof), for example, a communication network. Examplesof interconnected devices are a client and a server generally remotefrom each other that typically interact through a communication network.A client, for example, a mobile device, can carry out transactionsitself, with a server, or through a server, for example, performing buy,sell, pay, give, send, or loan transactions, or authorizing the same.Such transactions may be in real time such that an action and a responseare temporally proximate; for example an individual perceives the actionand the response occurring substantially simultaneously, the timedifference for a response following the individual's action is less than1 millisecond (ms) or less than 1 second (s), or the response is withoutintentional delay taking into account processing limitations of thesystem.

Examples of communication networks include a local area network (LAN), aradio access network (RAN), a metropolitan area network (MAN), and awide area network (WAN). The communication network can include all or aportion of the Internet, another communication network, or a combinationof communication networks. Information can be transmitted on thecommunication network according to various protocols and standards,including Long Term Evolution (LTE), 5G, IEEE 802, Internet Protocol(IP), or other protocols or combinations of protocols. The communicationnetwork can transmit voice, video, biometric, or authentication data, orother information between the connected computing devices.

Features described as separate implementations may be implemented, incombination, in a single implementation, while features described as asingle implementation may be implemented in multiple implementations,separately, or in any suitable sub-combination. Operations described andclaimed in a particular order should not be understood as requiring thatthe particular order, nor that all illustrated operations must beperformed (some operations can be optional). As appropriate,multitasking or parallel-processing (or a combination of multitaskingand parallel-processing) can be performed.

What is claimed is:
 1. A computer-implemented method, comprising:receiving, at a node device associated with a blockchain as a receivedtarget transaction, a target transaction published by a user, whereinthe received target transaction comprises transaction content, andwherein at least a part of the transaction content comprises a contentsummary associated with target content that is stored in a third-partystorage system connected to the blockchain; querying, by the node deviceand to the third-party storage system, the target content correspondingto the content summary; identifying, by the node device as identifiedtarget content, the target content corresponding to the content summaryin the received target transaction; recalculating, by the node device asrecalculated content summary, the content summary of the identifiedtarget content; determining, by the node device, that the recalculatedcontent summary does not match the content summary in the receivedtarget transaction; in response to determining that the recalculatedcontent summary does not match the content summary in the receivedtarget transaction, determining that the target content is not verifiedand that the received target transaction is invalid; and terminating, bythe node device, the received target transaction.
 2. Thecomputer-implemented method of claim 1, wherein the blockchain is amember blockchain associated with a consortium blockchain network,wherein the consortium blockchain network comprises a plurality ofmember blockchains, and wherein each member blockchain in the consortiumblockchain network is an additional third-party storage system connectedto another member blockchain to implement a cross-chain data reference.3. The computer-implemented method of claim 2, wherein the third-partystorage system comprises a content-addressable-storage (CAS) platformthat provides a data storage service for the plurality of the memberblockchains, wherein the CAS platform uses the content summary of thetarget content as a query index of the target content, and wherein theCAS platform stores a mapping relationship between the query index andthe target content.
 4. The computer-implemented method of claim 1,wherein determining the recalculated content summary does not match thecontent summary in the received target transaction comprises:determining that a first data structure corresponding to therecalculated content summary does not match a second data structurecorresponding to the content summary in the received target transaction.5. The computer-implemented method of claim 1, wherein determining therecalculated content summary does not match the content summary in thereceived target transaction comprises: determining that a first methodof encoding corresponding to the recalculated content summary does notmatch a second method of encoding corresponding to the content summaryin the received target transaction.
 6. The computer-implemented methodof claim 1, wherein determining the recalculated content summary doesnot match the content summary in the received target transactioncomprises: determining that a first summary algorithm corresponding tothe recalculated content summary does not match a second summaryalgorithm corresponding to the content summary in the received targettransaction.
 7. A non-transitory, computer-readable medium storing oneor more instructions executable by a computer system to performoperations comprising: receiving, at a node device associated with ablockchain as a received target transaction, a target transactionpublished by a user, wherein the received target transaction comprisestransaction content, and wherein at least a part of the transactioncontent comprises a content summary associated with target content thatis stored in a third-party storage system connected to the blockchain;querying, by the node device and to the third-party storage system, thetarget content corresponding to the content summary; identifying, by thenode device as identified target content, the target contentcorresponding to the content summary in the received target transaction;recalculating, by the node device as recalculated content summary, thecontent summary of the identified target content determining, by thenode device, that the recalculated content summary does not match thecontent summary in the received target transaction; in response todetermining that the recalculated content summary does not match thecontent summary in the received target transaction, determining that thetarget content is not verified and that the received target transactionis invalid; and terminating, by the node device, the received targettransaction.
 8. The non-transitory, computer-readable medium of claim 7,wherein the blockchain is a member blockchain associated with aconsortium blockchain network, wherein the consortium blockchain networkcomprises a plurality of member blockchains, and wherein each memberblockchain in the consortium blockchain network is an additionalthird-party storage system connected to another member blockchain toimplement a cross-chain data reference.
 9. The non-transitory,computer-readable medium of claim 8, wherein the third-party storagesystem comprises a content-addressable-storage (CAS) platform thatprovides a data storage service for the plurality of the memberblockchains, wherein the CAS platform uses the content summary of thetarget content as a query index of the target content, and wherein theCAS platform stores a mapping relationship between the query index andthe target content.
 10. The non-transitory, computer-readable medium ofclaim 7, wherein determining the recalculated content summary does notmatch the content summary in the received target transaction comprises:determining that a first data structure corresponding to therecalculated content summary does not match a second data structurecorresponding to the content summary in the received target transaction.11. The non-transitory, computer-readable medium of claim 7, whereindetermining the recalculated content summary does not match the contentsummary in the received target transaction comprises: determining that afirst method of encoding corresponding to the recalculated contentsummary does not match a second method of encoding corresponding to thecontent summary in the received target transaction.
 12. Thenon-transitory, computer-readable medium of claim 7, wherein determiningthe recalculated content summary does not match the content summary inthe received target transaction comprises: determining that a firstsummary algorithm corresponding to the recalculated content summary doesnot match a second summary algorithm corresponding to the contentsummary in the received target transaction.
 13. A computer-implementedsystem, comprising: one or more computers; and one or more computermemory devices interoperably coupled with the one or more computers andhaving tangible, non-transitory, machine-readable media storing one ormore instructions that, when executed by the one or more computers,perform one or more operations comprising: receiving, at a node deviceassociated with a blockchain as a received target transaction, a targettransaction published by a user, wherein the received target transactioncomprises transaction content, and wherein at least a part of thetransaction content comprises a content summary associated with targetcontent that is stored in a third-party storage system connected to theblockchain; querying, by the node device and to the third-party storagesystem, the target content corresponding to the content summary;identifying, by the node device as identified target content, the targetcontent corresponding to the content summary in the received targettransaction; recalculating, by the node device as recalculated contentsummary, the content summary of the identified target contentdetermining, by the node device, that the recalculated content summarydoes not match the content summary in the received target transaction;in response to determining that the recalculated content summary doesnot match the content summary in the received target transaction,determining that the target content is not verified and that thereceived target transaction is invalid; and terminating, by the nodedevice, the received target transaction.
 14. The computer-implementedsystem of claim 13, wherein the blockchain is a member blockchainassociated with a consortium blockchain network, wherein the consortiumblockchain network comprises a plurality of member blockchains, andwherein each member blockchain in the consortium blockchain network isan additional third-party storage system connected to another memberblockchain to implement a cross-chain data reference.
 15. Thecomputer-implemented system of claim 14, wherein the third-party storagesystem comprises a content-addressable-storage (CAS) platform thatprovides a data storage service for the plurality of the memberblockchains, wherein the CAS platform uses the content summary of thetarget content as a query index of the target content, and wherein theCAS platform stores a mapping relationship between the query index andthe target content.
 16. The computer-implemented system of claim 13,wherein determining the recalculated content summary does not match thecontent summary in the received target transaction comprises:determining that a first data structure corresponding to therecalculated content summary does not match a second data structurecorresponding to the content summary in the received target transaction.17. The computer-implemented system of claim 13, wherein determining therecalculated content summary does not match the content summary in thereceived target transaction comprises: determining that a first methodof encoding corresponding to the recalculated content summary does notmatch a second method of encoding corresponding to the content summaryin the received target transaction.
 18. The computer-implemented systemof claim 13, wherein determining the recalculated content summary doesnot match the content summary in the received target transactioncomprises: determining that a first summary algorithm corresponding tothe recalculated content summary does not match a second summaryalgorithm corresponding to the content summary in the received targettransaction.